Abstract

We have studied the metal–insulator transition (MIT) taking place at 340 K in vanadium dioxide nanoparticles. A peculiar nanosize effect on the 10-nm-sized nanoparticles is reported. While the infrared transmittance at high wave numbers displayed a broad transition behavior, the magnetic susceptibility and infrared transmittance at low wave numbers showed a sharp first-order MIT. Our results suggest that the size effect on the MIT is due to the surface region while the core region undergoes the same MIT as that in the bulk.

Received 15 March 2010Accepted 25 May 2010Published online 18 June 2010

Acknowledgments:

This work was supported by the Korea Ministry of Education, Science, and Technology (NRL Program R0A-2008-000-20066-0 and Project No. 20090082672) and by the Seoul Research and Business Development Program (Grant No. 10583). The measurements at the Korean Basic Science Institute (KBSI) are acknowledged.